1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/sch_api.c Packet scheduler API. 4 * 5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 6 * 7 * Fixes: 8 * 9 * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired. 10 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 11 * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support 12 */ 13 14 #include <linux/module.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/skbuff.h> 20 #include <linux/init.h> 21 #include <linux/proc_fs.h> 22 #include <linux/seq_file.h> 23 #include <linux/kmod.h> 24 #include <linux/list.h> 25 #include <linux/hrtimer.h> 26 #include <linux/slab.h> 27 #include <linux/hashtable.h> 28 29 #include <net/net_namespace.h> 30 #include <net/sock.h> 31 #include <net/netlink.h> 32 #include <net/pkt_sched.h> 33 #include <net/pkt_cls.h> 34 #include <net/tc_wrapper.h> 35 36 #include <trace/events/qdisc.h> 37 38 /* 39 40 Short review. 41 ------------- 42 43 This file consists of two interrelated parts: 44 45 1. queueing disciplines manager frontend. 46 2. traffic classes manager frontend. 47 48 Generally, queueing discipline ("qdisc") is a black box, 49 which is able to enqueue packets and to dequeue them (when 50 device is ready to send something) in order and at times 51 determined by algorithm hidden in it. 52 53 qdisc's are divided to two categories: 54 - "queues", which have no internal structure visible from outside. 55 - "schedulers", which split all the packets to "traffic classes", 56 using "packet classifiers" (look at cls_api.c) 57 58 In turn, classes may have child qdiscs (as rule, queues) 59 attached to them etc. etc. etc. 60 61 The goal of the routines in this file is to translate 62 information supplied by user in the form of handles 63 to more intelligible for kernel form, to make some sanity 64 checks and part of work, which is common to all qdiscs 65 and to provide rtnetlink notifications. 66 67 All real intelligent work is done inside qdisc modules. 68 69 70 71 Every discipline has two major routines: enqueue and dequeue. 72 73 ---dequeue 74 75 dequeue usually returns a skb to send. It is allowed to return NULL, 76 but it does not mean that queue is empty, it just means that 77 discipline does not want to send anything this time. 78 Queue is really empty if q->q.qlen == 0. 79 For complicated disciplines with multiple queues q->q is not 80 real packet queue, but however q->q.qlen must be valid. 81 82 ---enqueue 83 84 enqueue returns 0, if packet was enqueued successfully. 85 If packet (this one or another one) was dropped, it returns 86 not zero error code. 87 NET_XMIT_DROP - this packet dropped 88 Expected action: do not backoff, but wait until queue will clear. 89 NET_XMIT_CN - probably this packet enqueued, but another one dropped. 90 Expected action: backoff or ignore 91 92 Auxiliary routines: 93 94 ---peek 95 96 like dequeue but without removing a packet from the queue 97 98 ---reset 99 100 returns qdisc to initial state: purge all buffers, clear all 101 timers, counters (except for statistics) etc. 102 103 ---init 104 105 initializes newly created qdisc. 106 107 ---destroy 108 109 destroys resources allocated by init and during lifetime of qdisc. 110 111 ---change 112 113 changes qdisc parameters. 114 */ 115 116 /* Protects list of registered TC modules. It is pure SMP lock. */ 117 static DEFINE_RWLOCK(qdisc_mod_lock); 118 119 120 /************************************************ 121 * Queueing disciplines manipulation. * 122 ************************************************/ 123 124 125 /* The list of all installed queueing disciplines. */ 126 127 static struct Qdisc_ops *qdisc_base; 128 129 /* Register/unregister queueing discipline */ 130 131 int register_qdisc(struct Qdisc_ops *qops) 132 { 133 struct Qdisc_ops *q, **qp; 134 int rc = -EEXIST; 135 136 write_lock(&qdisc_mod_lock); 137 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 138 if (!strcmp(qops->id, q->id)) 139 goto out; 140 141 if (qops->enqueue == NULL) 142 qops->enqueue = noop_qdisc_ops.enqueue; 143 if (qops->peek == NULL) { 144 if (qops->dequeue == NULL) 145 qops->peek = noop_qdisc_ops.peek; 146 else 147 goto out_einval; 148 } 149 if (qops->dequeue == NULL) 150 qops->dequeue = noop_qdisc_ops.dequeue; 151 152 if (qops->cl_ops) { 153 const struct Qdisc_class_ops *cops = qops->cl_ops; 154 155 if (!(cops->find && cops->walk && cops->leaf)) 156 goto out_einval; 157 158 if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf)) 159 goto out_einval; 160 } 161 162 qops->next = NULL; 163 *qp = qops; 164 rc = 0; 165 out: 166 write_unlock(&qdisc_mod_lock); 167 return rc; 168 169 out_einval: 170 rc = -EINVAL; 171 goto out; 172 } 173 EXPORT_SYMBOL(register_qdisc); 174 175 void unregister_qdisc(struct Qdisc_ops *qops) 176 { 177 struct Qdisc_ops *q, **qp; 178 int err = -ENOENT; 179 180 write_lock(&qdisc_mod_lock); 181 for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) 182 if (q == qops) 183 break; 184 if (q) { 185 *qp = q->next; 186 q->next = NULL; 187 err = 0; 188 } 189 write_unlock(&qdisc_mod_lock); 190 191 WARN(err, "unregister qdisc(%s) failed\n", qops->id); 192 } 193 EXPORT_SYMBOL(unregister_qdisc); 194 195 /* Get default qdisc if not otherwise specified */ 196 void qdisc_get_default(char *name, size_t len) 197 { 198 read_lock(&qdisc_mod_lock); 199 strscpy(name, default_qdisc_ops->id, len); 200 read_unlock(&qdisc_mod_lock); 201 } 202 203 static struct Qdisc_ops *qdisc_lookup_default(const char *name) 204 { 205 struct Qdisc_ops *q = NULL; 206 207 for (q = qdisc_base; q; q = q->next) { 208 if (!strcmp(name, q->id)) { 209 if (!try_module_get(q->owner)) 210 q = NULL; 211 break; 212 } 213 } 214 215 return q; 216 } 217 218 /* Set new default qdisc to use */ 219 int qdisc_set_default(const char *name) 220 { 221 const struct Qdisc_ops *ops; 222 223 if (!capable(CAP_NET_ADMIN)) 224 return -EPERM; 225 226 write_lock(&qdisc_mod_lock); 227 ops = qdisc_lookup_default(name); 228 if (!ops) { 229 /* Not found, drop lock and try to load module */ 230 write_unlock(&qdisc_mod_lock); 231 request_module("sch_%s", name); 232 write_lock(&qdisc_mod_lock); 233 234 ops = qdisc_lookup_default(name); 235 } 236 237 if (ops) { 238 /* Set new default */ 239 module_put(default_qdisc_ops->owner); 240 default_qdisc_ops = ops; 241 } 242 write_unlock(&qdisc_mod_lock); 243 244 return ops ? 0 : -ENOENT; 245 } 246 247 #ifdef CONFIG_NET_SCH_DEFAULT 248 /* Set default value from kernel config */ 249 static int __init sch_default_qdisc(void) 250 { 251 return qdisc_set_default(CONFIG_DEFAULT_NET_SCH); 252 } 253 late_initcall(sch_default_qdisc); 254 #endif 255 256 /* We know handle. Find qdisc among all qdisc's attached to device 257 * (root qdisc, all its children, children of children etc.) 258 * Note: caller either uses rtnl or rcu_read_lock() 259 */ 260 261 static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle) 262 { 263 struct Qdisc *q; 264 265 if (!qdisc_dev(root)) 266 return (root->handle == handle ? root : NULL); 267 268 if (!(root->flags & TCQ_F_BUILTIN) && 269 root->handle == handle) 270 return root; 271 272 hash_for_each_possible_rcu(qdisc_dev(root)->qdisc_hash, q, hash, handle, 273 lockdep_rtnl_is_held()) { 274 if (q->handle == handle) 275 return q; 276 } 277 return NULL; 278 } 279 280 void qdisc_hash_add(struct Qdisc *q, bool invisible) 281 { 282 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 283 ASSERT_RTNL(); 284 hash_add_rcu(qdisc_dev(q)->qdisc_hash, &q->hash, q->handle); 285 if (invisible) 286 q->flags |= TCQ_F_INVISIBLE; 287 } 288 } 289 EXPORT_SYMBOL(qdisc_hash_add); 290 291 void qdisc_hash_del(struct Qdisc *q) 292 { 293 if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS)) { 294 ASSERT_RTNL(); 295 hash_del_rcu(&q->hash); 296 } 297 } 298 EXPORT_SYMBOL(qdisc_hash_del); 299 300 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle) 301 { 302 struct Qdisc *q; 303 304 if (!handle) 305 return NULL; 306 q = qdisc_match_from_root(rtnl_dereference(dev->qdisc), handle); 307 if (q) 308 goto out; 309 310 if (dev_ingress_queue(dev)) 311 q = qdisc_match_from_root( 312 rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping), 313 handle); 314 out: 315 return q; 316 } 317 318 struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle) 319 { 320 struct netdev_queue *nq; 321 struct Qdisc *q; 322 323 if (!handle) 324 return NULL; 325 q = qdisc_match_from_root(rcu_dereference(dev->qdisc), handle); 326 if (q) 327 goto out; 328 329 nq = dev_ingress_queue_rcu(dev); 330 if (nq) 331 q = qdisc_match_from_root(rcu_dereference(nq->qdisc_sleeping), 332 handle); 333 out: 334 return q; 335 } 336 337 static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid) 338 { 339 unsigned long cl; 340 const struct Qdisc_class_ops *cops = p->ops->cl_ops; 341 342 if (cops == NULL) 343 return NULL; 344 cl = cops->find(p, classid); 345 346 if (cl == 0) 347 return NULL; 348 return cops->leaf(p, cl); 349 } 350 351 /* Find queueing discipline by name */ 352 353 static struct Qdisc_ops *qdisc_lookup_ops(struct nlattr *kind) 354 { 355 struct Qdisc_ops *q = NULL; 356 357 if (kind) { 358 read_lock(&qdisc_mod_lock); 359 for (q = qdisc_base; q; q = q->next) { 360 if (nla_strcmp(kind, q->id) == 0) { 361 if (!try_module_get(q->owner)) 362 q = NULL; 363 break; 364 } 365 } 366 read_unlock(&qdisc_mod_lock); 367 } 368 return q; 369 } 370 371 /* The linklayer setting were not transferred from iproute2, in older 372 * versions, and the rate tables lookup systems have been dropped in 373 * the kernel. To keep backward compatible with older iproute2 tc 374 * utils, we detect the linklayer setting by detecting if the rate 375 * table were modified. 376 * 377 * For linklayer ATM table entries, the rate table will be aligned to 378 * 48 bytes, thus some table entries will contain the same value. The 379 * mpu (min packet unit) is also encoded into the old rate table, thus 380 * starting from the mpu, we find low and high table entries for 381 * mapping this cell. If these entries contain the same value, when 382 * the rate tables have been modified for linklayer ATM. 383 * 384 * This is done by rounding mpu to the nearest 48 bytes cell/entry, 385 * and then roundup to the next cell, calc the table entry one below, 386 * and compare. 387 */ 388 static __u8 __detect_linklayer(struct tc_ratespec *r, __u32 *rtab) 389 { 390 int low = roundup(r->mpu, 48); 391 int high = roundup(low+1, 48); 392 int cell_low = low >> r->cell_log; 393 int cell_high = (high >> r->cell_log) - 1; 394 395 /* rtab is too inaccurate at rates > 100Mbit/s */ 396 if ((r->rate > (100000000/8)) || (rtab[0] == 0)) { 397 pr_debug("TC linklayer: Giving up ATM detection\n"); 398 return TC_LINKLAYER_ETHERNET; 399 } 400 401 if ((cell_high > cell_low) && (cell_high < 256) 402 && (rtab[cell_low] == rtab[cell_high])) { 403 pr_debug("TC linklayer: Detected ATM, low(%d)=high(%d)=%u\n", 404 cell_low, cell_high, rtab[cell_high]); 405 return TC_LINKLAYER_ATM; 406 } 407 return TC_LINKLAYER_ETHERNET; 408 } 409 410 static struct qdisc_rate_table *qdisc_rtab_list; 411 412 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, 413 struct nlattr *tab, 414 struct netlink_ext_ack *extack) 415 { 416 struct qdisc_rate_table *rtab; 417 418 if (tab == NULL || r->rate == 0 || 419 r->cell_log == 0 || r->cell_log >= 32 || 420 nla_len(tab) != TC_RTAB_SIZE) { 421 NL_SET_ERR_MSG(extack, "Invalid rate table parameters for searching"); 422 return NULL; 423 } 424 425 for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) { 426 if (!memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) && 427 !memcmp(&rtab->data, nla_data(tab), 1024)) { 428 rtab->refcnt++; 429 return rtab; 430 } 431 } 432 433 rtab = kmalloc(sizeof(*rtab), GFP_KERNEL); 434 if (rtab) { 435 rtab->rate = *r; 436 rtab->refcnt = 1; 437 memcpy(rtab->data, nla_data(tab), 1024); 438 if (r->linklayer == TC_LINKLAYER_UNAWARE) 439 r->linklayer = __detect_linklayer(r, rtab->data); 440 rtab->next = qdisc_rtab_list; 441 qdisc_rtab_list = rtab; 442 } else { 443 NL_SET_ERR_MSG(extack, "Failed to allocate new qdisc rate table"); 444 } 445 return rtab; 446 } 447 EXPORT_SYMBOL(qdisc_get_rtab); 448 449 void qdisc_put_rtab(struct qdisc_rate_table *tab) 450 { 451 struct qdisc_rate_table *rtab, **rtabp; 452 453 if (!tab || --tab->refcnt) 454 return; 455 456 for (rtabp = &qdisc_rtab_list; 457 (rtab = *rtabp) != NULL; 458 rtabp = &rtab->next) { 459 if (rtab == tab) { 460 *rtabp = rtab->next; 461 kfree(rtab); 462 return; 463 } 464 } 465 } 466 EXPORT_SYMBOL(qdisc_put_rtab); 467 468 static LIST_HEAD(qdisc_stab_list); 469 470 static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = { 471 [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) }, 472 [TCA_STAB_DATA] = { .type = NLA_BINARY }, 473 }; 474 475 static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt, 476 struct netlink_ext_ack *extack) 477 { 478 struct nlattr *tb[TCA_STAB_MAX + 1]; 479 struct qdisc_size_table *stab; 480 struct tc_sizespec *s; 481 unsigned int tsize = 0; 482 u16 *tab = NULL; 483 int err; 484 485 err = nla_parse_nested_deprecated(tb, TCA_STAB_MAX, opt, stab_policy, 486 extack); 487 if (err < 0) 488 return ERR_PTR(err); 489 if (!tb[TCA_STAB_BASE]) { 490 NL_SET_ERR_MSG(extack, "Size table base attribute is missing"); 491 return ERR_PTR(-EINVAL); 492 } 493 494 s = nla_data(tb[TCA_STAB_BASE]); 495 496 if (s->tsize > 0) { 497 if (!tb[TCA_STAB_DATA]) { 498 NL_SET_ERR_MSG(extack, "Size table data attribute is missing"); 499 return ERR_PTR(-EINVAL); 500 } 501 tab = nla_data(tb[TCA_STAB_DATA]); 502 tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16); 503 } 504 505 if (tsize != s->tsize || (!tab && tsize > 0)) { 506 NL_SET_ERR_MSG(extack, "Invalid size of size table"); 507 return ERR_PTR(-EINVAL); 508 } 509 510 list_for_each_entry(stab, &qdisc_stab_list, list) { 511 if (memcmp(&stab->szopts, s, sizeof(*s))) 512 continue; 513 if (tsize > 0 && 514 memcmp(stab->data, tab, flex_array_size(stab, data, tsize))) 515 continue; 516 stab->refcnt++; 517 return stab; 518 } 519 520 if (s->size_log > STAB_SIZE_LOG_MAX || 521 s->cell_log > STAB_SIZE_LOG_MAX) { 522 NL_SET_ERR_MSG(extack, "Invalid logarithmic size of size table"); 523 return ERR_PTR(-EINVAL); 524 } 525 526 stab = kmalloc(struct_size(stab, data, tsize), GFP_KERNEL); 527 if (!stab) 528 return ERR_PTR(-ENOMEM); 529 530 stab->refcnt = 1; 531 stab->szopts = *s; 532 if (tsize > 0) 533 memcpy(stab->data, tab, flex_array_size(stab, data, tsize)); 534 535 list_add_tail(&stab->list, &qdisc_stab_list); 536 537 return stab; 538 } 539 540 void qdisc_put_stab(struct qdisc_size_table *tab) 541 { 542 if (!tab) 543 return; 544 545 if (--tab->refcnt == 0) { 546 list_del(&tab->list); 547 kfree_rcu(tab, rcu); 548 } 549 } 550 EXPORT_SYMBOL(qdisc_put_stab); 551 552 static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab) 553 { 554 struct nlattr *nest; 555 556 nest = nla_nest_start_noflag(skb, TCA_STAB); 557 if (nest == NULL) 558 goto nla_put_failure; 559 if (nla_put(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts)) 560 goto nla_put_failure; 561 nla_nest_end(skb, nest); 562 563 return skb->len; 564 565 nla_put_failure: 566 return -1; 567 } 568 569 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 570 const struct qdisc_size_table *stab) 571 { 572 int pkt_len, slot; 573 574 pkt_len = skb->len + stab->szopts.overhead; 575 if (unlikely(!stab->szopts.tsize)) 576 goto out; 577 578 slot = pkt_len + stab->szopts.cell_align; 579 if (unlikely(slot < 0)) 580 slot = 0; 581 582 slot >>= stab->szopts.cell_log; 583 if (likely(slot < stab->szopts.tsize)) 584 pkt_len = stab->data[slot]; 585 else 586 pkt_len = stab->data[stab->szopts.tsize - 1] * 587 (slot / stab->szopts.tsize) + 588 stab->data[slot % stab->szopts.tsize]; 589 590 pkt_len <<= stab->szopts.size_log; 591 out: 592 if (unlikely(pkt_len < 1)) 593 pkt_len = 1; 594 qdisc_skb_cb(skb)->pkt_len = pkt_len; 595 } 596 EXPORT_SYMBOL(__qdisc_calculate_pkt_len); 597 598 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc) 599 { 600 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) { 601 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n", 602 txt, qdisc->ops->id, qdisc->handle >> 16); 603 qdisc->flags |= TCQ_F_WARN_NONWC; 604 } 605 } 606 EXPORT_SYMBOL(qdisc_warn_nonwc); 607 608 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) 609 { 610 struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, 611 timer); 612 613 rcu_read_lock(); 614 __netif_schedule(qdisc_root(wd->qdisc)); 615 rcu_read_unlock(); 616 617 return HRTIMER_NORESTART; 618 } 619 620 void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc, 621 clockid_t clockid) 622 { 623 hrtimer_init(&wd->timer, clockid, HRTIMER_MODE_ABS_PINNED); 624 wd->timer.function = qdisc_watchdog; 625 wd->qdisc = qdisc; 626 } 627 EXPORT_SYMBOL(qdisc_watchdog_init_clockid); 628 629 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc) 630 { 631 qdisc_watchdog_init_clockid(wd, qdisc, CLOCK_MONOTONIC); 632 } 633 EXPORT_SYMBOL(qdisc_watchdog_init); 634 635 void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires, 636 u64 delta_ns) 637 { 638 bool deactivated; 639 640 rcu_read_lock(); 641 deactivated = test_bit(__QDISC_STATE_DEACTIVATED, 642 &qdisc_root_sleeping(wd->qdisc)->state); 643 rcu_read_unlock(); 644 if (deactivated) 645 return; 646 647 if (hrtimer_is_queued(&wd->timer)) { 648 u64 softexpires; 649 650 softexpires = ktime_to_ns(hrtimer_get_softexpires(&wd->timer)); 651 /* If timer is already set in [expires, expires + delta_ns], 652 * do not reprogram it. 653 */ 654 if (softexpires - expires <= delta_ns) 655 return; 656 } 657 658 hrtimer_start_range_ns(&wd->timer, 659 ns_to_ktime(expires), 660 delta_ns, 661 HRTIMER_MODE_ABS_PINNED); 662 } 663 EXPORT_SYMBOL(qdisc_watchdog_schedule_range_ns); 664 665 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd) 666 { 667 hrtimer_cancel(&wd->timer); 668 } 669 EXPORT_SYMBOL(qdisc_watchdog_cancel); 670 671 static struct hlist_head *qdisc_class_hash_alloc(unsigned int n) 672 { 673 struct hlist_head *h; 674 unsigned int i; 675 676 h = kvmalloc_array(n, sizeof(struct hlist_head), GFP_KERNEL); 677 678 if (h != NULL) { 679 for (i = 0; i < n; i++) 680 INIT_HLIST_HEAD(&h[i]); 681 } 682 return h; 683 } 684 685 void qdisc_class_hash_grow(struct Qdisc *sch, struct Qdisc_class_hash *clhash) 686 { 687 struct Qdisc_class_common *cl; 688 struct hlist_node *next; 689 struct hlist_head *nhash, *ohash; 690 unsigned int nsize, nmask, osize; 691 unsigned int i, h; 692 693 /* Rehash when load factor exceeds 0.75 */ 694 if (clhash->hashelems * 4 <= clhash->hashsize * 3) 695 return; 696 nsize = clhash->hashsize * 2; 697 nmask = nsize - 1; 698 nhash = qdisc_class_hash_alloc(nsize); 699 if (nhash == NULL) 700 return; 701 702 ohash = clhash->hash; 703 osize = clhash->hashsize; 704 705 sch_tree_lock(sch); 706 for (i = 0; i < osize; i++) { 707 hlist_for_each_entry_safe(cl, next, &ohash[i], hnode) { 708 h = qdisc_class_hash(cl->classid, nmask); 709 hlist_add_head(&cl->hnode, &nhash[h]); 710 } 711 } 712 clhash->hash = nhash; 713 clhash->hashsize = nsize; 714 clhash->hashmask = nmask; 715 sch_tree_unlock(sch); 716 717 kvfree(ohash); 718 } 719 EXPORT_SYMBOL(qdisc_class_hash_grow); 720 721 int qdisc_class_hash_init(struct Qdisc_class_hash *clhash) 722 { 723 unsigned int size = 4; 724 725 clhash->hash = qdisc_class_hash_alloc(size); 726 if (!clhash->hash) 727 return -ENOMEM; 728 clhash->hashsize = size; 729 clhash->hashmask = size - 1; 730 clhash->hashelems = 0; 731 return 0; 732 } 733 EXPORT_SYMBOL(qdisc_class_hash_init); 734 735 void qdisc_class_hash_destroy(struct Qdisc_class_hash *clhash) 736 { 737 kvfree(clhash->hash); 738 } 739 EXPORT_SYMBOL(qdisc_class_hash_destroy); 740 741 void qdisc_class_hash_insert(struct Qdisc_class_hash *clhash, 742 struct Qdisc_class_common *cl) 743 { 744 unsigned int h; 745 746 INIT_HLIST_NODE(&cl->hnode); 747 h = qdisc_class_hash(cl->classid, clhash->hashmask); 748 hlist_add_head(&cl->hnode, &clhash->hash[h]); 749 clhash->hashelems++; 750 } 751 EXPORT_SYMBOL(qdisc_class_hash_insert); 752 753 void qdisc_class_hash_remove(struct Qdisc_class_hash *clhash, 754 struct Qdisc_class_common *cl) 755 { 756 hlist_del(&cl->hnode); 757 clhash->hashelems--; 758 } 759 EXPORT_SYMBOL(qdisc_class_hash_remove); 760 761 /* Allocate an unique handle from space managed by kernel 762 * Possible range is [8000-FFFF]:0000 (0x8000 values) 763 */ 764 static u32 qdisc_alloc_handle(struct net_device *dev) 765 { 766 int i = 0x8000; 767 static u32 autohandle = TC_H_MAKE(0x80000000U, 0); 768 769 do { 770 autohandle += TC_H_MAKE(0x10000U, 0); 771 if (autohandle == TC_H_MAKE(TC_H_ROOT, 0)) 772 autohandle = TC_H_MAKE(0x80000000U, 0); 773 if (!qdisc_lookup(dev, autohandle)) 774 return autohandle; 775 cond_resched(); 776 } while (--i > 0); 777 778 return 0; 779 } 780 781 void qdisc_tree_reduce_backlog(struct Qdisc *sch, int n, int len) 782 { 783 bool qdisc_is_offloaded = sch->flags & TCQ_F_OFFLOADED; 784 const struct Qdisc_class_ops *cops; 785 unsigned long cl; 786 u32 parentid; 787 bool notify; 788 int drops; 789 790 if (n == 0 && len == 0) 791 return; 792 drops = max_t(int, n, 0); 793 rcu_read_lock(); 794 while ((parentid = sch->parent)) { 795 if (TC_H_MAJ(parentid) == TC_H_MAJ(TC_H_INGRESS)) 796 break; 797 798 if (sch->flags & TCQ_F_NOPARENT) 799 break; 800 /* Notify parent qdisc only if child qdisc becomes empty. 801 * 802 * If child was empty even before update then backlog 803 * counter is screwed and we skip notification because 804 * parent class is already passive. 805 * 806 * If the original child was offloaded then it is allowed 807 * to be seem as empty, so the parent is notified anyway. 808 */ 809 notify = !sch->q.qlen && !WARN_ON_ONCE(!n && 810 !qdisc_is_offloaded); 811 /* TODO: perform the search on a per txq basis */ 812 sch = qdisc_lookup_rcu(qdisc_dev(sch), TC_H_MAJ(parentid)); 813 if (sch == NULL) { 814 WARN_ON_ONCE(parentid != TC_H_ROOT); 815 break; 816 } 817 cops = sch->ops->cl_ops; 818 if (notify && cops->qlen_notify) { 819 cl = cops->find(sch, parentid); 820 cops->qlen_notify(sch, cl); 821 } 822 sch->q.qlen -= n; 823 sch->qstats.backlog -= len; 824 __qdisc_qstats_drop(sch, drops); 825 } 826 rcu_read_unlock(); 827 } 828 EXPORT_SYMBOL(qdisc_tree_reduce_backlog); 829 830 int qdisc_offload_dump_helper(struct Qdisc *sch, enum tc_setup_type type, 831 void *type_data) 832 { 833 struct net_device *dev = qdisc_dev(sch); 834 int err; 835 836 sch->flags &= ~TCQ_F_OFFLOADED; 837 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 838 return 0; 839 840 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 841 if (err == -EOPNOTSUPP) 842 return 0; 843 844 if (!err) 845 sch->flags |= TCQ_F_OFFLOADED; 846 847 return err; 848 } 849 EXPORT_SYMBOL(qdisc_offload_dump_helper); 850 851 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch, 852 struct Qdisc *new, struct Qdisc *old, 853 enum tc_setup_type type, void *type_data, 854 struct netlink_ext_ack *extack) 855 { 856 bool any_qdisc_is_offloaded; 857 int err; 858 859 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) 860 return; 861 862 err = dev->netdev_ops->ndo_setup_tc(dev, type, type_data); 863 864 /* Don't report error if the graft is part of destroy operation. */ 865 if (!err || !new || new == &noop_qdisc) 866 return; 867 868 /* Don't report error if the parent, the old child and the new 869 * one are not offloaded. 870 */ 871 any_qdisc_is_offloaded = new->flags & TCQ_F_OFFLOADED; 872 any_qdisc_is_offloaded |= sch && sch->flags & TCQ_F_OFFLOADED; 873 any_qdisc_is_offloaded |= old && old->flags & TCQ_F_OFFLOADED; 874 875 if (any_qdisc_is_offloaded) 876 NL_SET_ERR_MSG(extack, "Offloading graft operation failed."); 877 } 878 EXPORT_SYMBOL(qdisc_offload_graft_helper); 879 880 void qdisc_offload_query_caps(struct net_device *dev, 881 enum tc_setup_type type, 882 void *caps, size_t caps_len) 883 { 884 const struct net_device_ops *ops = dev->netdev_ops; 885 struct tc_query_caps_base base = { 886 .type = type, 887 .caps = caps, 888 }; 889 890 memset(caps, 0, caps_len); 891 892 if (ops->ndo_setup_tc) 893 ops->ndo_setup_tc(dev, TC_QUERY_CAPS, &base); 894 } 895 EXPORT_SYMBOL(qdisc_offload_query_caps); 896 897 static void qdisc_offload_graft_root(struct net_device *dev, 898 struct Qdisc *new, struct Qdisc *old, 899 struct netlink_ext_ack *extack) 900 { 901 struct tc_root_qopt_offload graft_offload = { 902 .command = TC_ROOT_GRAFT, 903 .handle = new ? new->handle : 0, 904 .ingress = (new && new->flags & TCQ_F_INGRESS) || 905 (old && old->flags & TCQ_F_INGRESS), 906 }; 907 908 qdisc_offload_graft_helper(dev, NULL, new, old, 909 TC_SETUP_ROOT_QDISC, &graft_offload, extack); 910 } 911 912 static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, 913 u32 portid, u32 seq, u16 flags, int event, 914 struct netlink_ext_ack *extack) 915 { 916 struct gnet_stats_basic_sync __percpu *cpu_bstats = NULL; 917 struct gnet_stats_queue __percpu *cpu_qstats = NULL; 918 struct tcmsg *tcm; 919 struct nlmsghdr *nlh; 920 unsigned char *b = skb_tail_pointer(skb); 921 struct gnet_dump d; 922 struct qdisc_size_table *stab; 923 u32 block_index; 924 __u32 qlen; 925 926 cond_resched(); 927 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 928 if (!nlh) 929 goto out_nlmsg_trim; 930 tcm = nlmsg_data(nlh); 931 tcm->tcm_family = AF_UNSPEC; 932 tcm->tcm__pad1 = 0; 933 tcm->tcm__pad2 = 0; 934 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 935 tcm->tcm_parent = clid; 936 tcm->tcm_handle = q->handle; 937 tcm->tcm_info = refcount_read(&q->refcnt); 938 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 939 goto nla_put_failure; 940 if (q->ops->ingress_block_get) { 941 block_index = q->ops->ingress_block_get(q); 942 if (block_index && 943 nla_put_u32(skb, TCA_INGRESS_BLOCK, block_index)) 944 goto nla_put_failure; 945 } 946 if (q->ops->egress_block_get) { 947 block_index = q->ops->egress_block_get(q); 948 if (block_index && 949 nla_put_u32(skb, TCA_EGRESS_BLOCK, block_index)) 950 goto nla_put_failure; 951 } 952 if (q->ops->dump && q->ops->dump(q, skb) < 0) 953 goto nla_put_failure; 954 if (nla_put_u8(skb, TCA_HW_OFFLOAD, !!(q->flags & TCQ_F_OFFLOADED))) 955 goto nla_put_failure; 956 qlen = qdisc_qlen_sum(q); 957 958 stab = rtnl_dereference(q->stab); 959 if (stab && qdisc_dump_stab(skb, stab) < 0) 960 goto nla_put_failure; 961 962 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 963 NULL, &d, TCA_PAD) < 0) 964 goto nla_put_failure; 965 966 if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) 967 goto nla_put_failure; 968 969 if (qdisc_is_percpu_stats(q)) { 970 cpu_bstats = q->cpu_bstats; 971 cpu_qstats = q->cpu_qstats; 972 } 973 974 if (gnet_stats_copy_basic(&d, cpu_bstats, &q->bstats, true) < 0 || 975 gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 || 976 gnet_stats_copy_queue(&d, cpu_qstats, &q->qstats, qlen) < 0) 977 goto nla_put_failure; 978 979 if (gnet_stats_finish_copy(&d) < 0) 980 goto nla_put_failure; 981 982 if (extack && extack->_msg && 983 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 984 goto out_nlmsg_trim; 985 986 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 987 988 return skb->len; 989 990 out_nlmsg_trim: 991 nla_put_failure: 992 nlmsg_trim(skb, b); 993 return -1; 994 } 995 996 static bool tc_qdisc_dump_ignore(struct Qdisc *q, bool dump_invisible) 997 { 998 if (q->flags & TCQ_F_BUILTIN) 999 return true; 1000 if ((q->flags & TCQ_F_INVISIBLE) && !dump_invisible) 1001 return true; 1002 1003 return false; 1004 } 1005 1006 static int qdisc_notify(struct net *net, struct sk_buff *oskb, 1007 struct nlmsghdr *n, u32 clid, 1008 struct Qdisc *old, struct Qdisc *new, 1009 struct netlink_ext_ack *extack) 1010 { 1011 struct sk_buff *skb; 1012 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1013 1014 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1015 if (!skb) 1016 return -ENOBUFS; 1017 1018 if (old && !tc_qdisc_dump_ignore(old, false)) { 1019 if (tc_fill_qdisc(skb, old, clid, portid, n->nlmsg_seq, 1020 0, RTM_DELQDISC, extack) < 0) 1021 goto err_out; 1022 } 1023 if (new && !tc_qdisc_dump_ignore(new, false)) { 1024 if (tc_fill_qdisc(skb, new, clid, portid, n->nlmsg_seq, 1025 old ? NLM_F_REPLACE : 0, RTM_NEWQDISC, extack) < 0) 1026 goto err_out; 1027 } 1028 1029 if (skb->len) 1030 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1031 n->nlmsg_flags & NLM_F_ECHO); 1032 1033 err_out: 1034 kfree_skb(skb); 1035 return -EINVAL; 1036 } 1037 1038 static void notify_and_destroy(struct net *net, struct sk_buff *skb, 1039 struct nlmsghdr *n, u32 clid, 1040 struct Qdisc *old, struct Qdisc *new, 1041 struct netlink_ext_ack *extack) 1042 { 1043 if (new || old) 1044 qdisc_notify(net, skb, n, clid, old, new, extack); 1045 1046 if (old) 1047 qdisc_put(old); 1048 } 1049 1050 static void qdisc_clear_nolock(struct Qdisc *sch) 1051 { 1052 sch->flags &= ~TCQ_F_NOLOCK; 1053 if (!(sch->flags & TCQ_F_CPUSTATS)) 1054 return; 1055 1056 free_percpu(sch->cpu_bstats); 1057 free_percpu(sch->cpu_qstats); 1058 sch->cpu_bstats = NULL; 1059 sch->cpu_qstats = NULL; 1060 sch->flags &= ~TCQ_F_CPUSTATS; 1061 } 1062 1063 /* Graft qdisc "new" to class "classid" of qdisc "parent" or 1064 * to device "dev". 1065 * 1066 * When appropriate send a netlink notification using 'skb' 1067 * and "n". 1068 * 1069 * On success, destroy old qdisc. 1070 */ 1071 1072 static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, 1073 struct sk_buff *skb, struct nlmsghdr *n, u32 classid, 1074 struct Qdisc *new, struct Qdisc *old, 1075 struct netlink_ext_ack *extack) 1076 { 1077 struct Qdisc *q = old; 1078 struct net *net = dev_net(dev); 1079 1080 if (parent == NULL) { 1081 unsigned int i, num_q, ingress; 1082 struct netdev_queue *dev_queue; 1083 1084 ingress = 0; 1085 num_q = dev->num_tx_queues; 1086 if ((q && q->flags & TCQ_F_INGRESS) || 1087 (new && new->flags & TCQ_F_INGRESS)) { 1088 ingress = 1; 1089 dev_queue = dev_ingress_queue(dev); 1090 if (!dev_queue) { 1091 NL_SET_ERR_MSG(extack, "Device does not have an ingress queue"); 1092 return -ENOENT; 1093 } 1094 1095 q = rtnl_dereference(dev_queue->qdisc_sleeping); 1096 1097 /* This is the counterpart of that qdisc_refcount_inc_nz() call in 1098 * __tcf_qdisc_find() for filter requests. 1099 */ 1100 if (!qdisc_refcount_dec_if_one(q)) { 1101 NL_SET_ERR_MSG(extack, 1102 "Current ingress or clsact Qdisc has ongoing filter requests"); 1103 return -EBUSY; 1104 } 1105 } 1106 1107 if (dev->flags & IFF_UP) 1108 dev_deactivate(dev); 1109 1110 qdisc_offload_graft_root(dev, new, old, extack); 1111 1112 if (new && new->ops->attach && !ingress) 1113 goto skip; 1114 1115 if (!ingress) { 1116 for (i = 0; i < num_q; i++) { 1117 dev_queue = netdev_get_tx_queue(dev, i); 1118 old = dev_graft_qdisc(dev_queue, new); 1119 1120 if (new && i > 0) 1121 qdisc_refcount_inc(new); 1122 qdisc_put(old); 1123 } 1124 } else { 1125 old = dev_graft_qdisc(dev_queue, NULL); 1126 1127 /* {ingress,clsact}_destroy() @old before grafting @new to avoid 1128 * unprotected concurrent accesses to net_device::miniq_{in,e}gress 1129 * pointer(s) in mini_qdisc_pair_swap(). 1130 */ 1131 qdisc_notify(net, skb, n, classid, old, new, extack); 1132 qdisc_destroy(old); 1133 1134 dev_graft_qdisc(dev_queue, new); 1135 } 1136 1137 skip: 1138 if (!ingress) { 1139 old = rtnl_dereference(dev->qdisc); 1140 if (new && !new->ops->attach) 1141 qdisc_refcount_inc(new); 1142 rcu_assign_pointer(dev->qdisc, new ? : &noop_qdisc); 1143 1144 notify_and_destroy(net, skb, n, classid, old, new, extack); 1145 1146 if (new && new->ops->attach) 1147 new->ops->attach(new); 1148 } 1149 1150 if (dev->flags & IFF_UP) 1151 dev_activate(dev); 1152 } else { 1153 const struct Qdisc_class_ops *cops = parent->ops->cl_ops; 1154 unsigned long cl; 1155 int err; 1156 1157 /* Only support running class lockless if parent is lockless */ 1158 if (new && (new->flags & TCQ_F_NOLOCK) && !(parent->flags & TCQ_F_NOLOCK)) 1159 qdisc_clear_nolock(new); 1160 1161 if (!cops || !cops->graft) 1162 return -EOPNOTSUPP; 1163 1164 cl = cops->find(parent, classid); 1165 if (!cl) { 1166 NL_SET_ERR_MSG(extack, "Specified class not found"); 1167 return -ENOENT; 1168 } 1169 1170 if (new && new->ops == &noqueue_qdisc_ops) { 1171 NL_SET_ERR_MSG(extack, "Cannot assign noqueue to a class"); 1172 return -EINVAL; 1173 } 1174 1175 err = cops->graft(parent, cl, new, &old, extack); 1176 if (err) 1177 return err; 1178 notify_and_destroy(net, skb, n, classid, old, new, extack); 1179 } 1180 return 0; 1181 } 1182 1183 static int qdisc_block_indexes_set(struct Qdisc *sch, struct nlattr **tca, 1184 struct netlink_ext_ack *extack) 1185 { 1186 u32 block_index; 1187 1188 if (tca[TCA_INGRESS_BLOCK]) { 1189 block_index = nla_get_u32(tca[TCA_INGRESS_BLOCK]); 1190 1191 if (!block_index) { 1192 NL_SET_ERR_MSG(extack, "Ingress block index cannot be 0"); 1193 return -EINVAL; 1194 } 1195 if (!sch->ops->ingress_block_set) { 1196 NL_SET_ERR_MSG(extack, "Ingress block sharing is not supported"); 1197 return -EOPNOTSUPP; 1198 } 1199 sch->ops->ingress_block_set(sch, block_index); 1200 } 1201 if (tca[TCA_EGRESS_BLOCK]) { 1202 block_index = nla_get_u32(tca[TCA_EGRESS_BLOCK]); 1203 1204 if (!block_index) { 1205 NL_SET_ERR_MSG(extack, "Egress block index cannot be 0"); 1206 return -EINVAL; 1207 } 1208 if (!sch->ops->egress_block_set) { 1209 NL_SET_ERR_MSG(extack, "Egress block sharing is not supported"); 1210 return -EOPNOTSUPP; 1211 } 1212 sch->ops->egress_block_set(sch, block_index); 1213 } 1214 return 0; 1215 } 1216 1217 /* 1218 Allocate and initialize new qdisc. 1219 1220 Parameters are passed via opt. 1221 */ 1222 1223 static struct Qdisc *qdisc_create(struct net_device *dev, 1224 struct netdev_queue *dev_queue, 1225 u32 parent, u32 handle, 1226 struct nlattr **tca, int *errp, 1227 struct netlink_ext_ack *extack) 1228 { 1229 int err; 1230 struct nlattr *kind = tca[TCA_KIND]; 1231 struct Qdisc *sch; 1232 struct Qdisc_ops *ops; 1233 struct qdisc_size_table *stab; 1234 1235 ops = qdisc_lookup_ops(kind); 1236 #ifdef CONFIG_MODULES 1237 if (ops == NULL && kind != NULL) { 1238 char name[IFNAMSIZ]; 1239 if (nla_strscpy(name, kind, IFNAMSIZ) >= 0) { 1240 /* We dropped the RTNL semaphore in order to 1241 * perform the module load. So, even if we 1242 * succeeded in loading the module we have to 1243 * tell the caller to replay the request. We 1244 * indicate this using -EAGAIN. 1245 * We replay the request because the device may 1246 * go away in the mean time. 1247 */ 1248 rtnl_unlock(); 1249 request_module("sch_%s", name); 1250 rtnl_lock(); 1251 ops = qdisc_lookup_ops(kind); 1252 if (ops != NULL) { 1253 /* We will try again qdisc_lookup_ops, 1254 * so don't keep a reference. 1255 */ 1256 module_put(ops->owner); 1257 err = -EAGAIN; 1258 goto err_out; 1259 } 1260 } 1261 } 1262 #endif 1263 1264 err = -ENOENT; 1265 if (!ops) { 1266 NL_SET_ERR_MSG(extack, "Specified qdisc kind is unknown"); 1267 goto err_out; 1268 } 1269 1270 sch = qdisc_alloc(dev_queue, ops, extack); 1271 if (IS_ERR(sch)) { 1272 err = PTR_ERR(sch); 1273 goto err_out2; 1274 } 1275 1276 sch->parent = parent; 1277 1278 if (handle == TC_H_INGRESS) { 1279 if (!(sch->flags & TCQ_F_INGRESS)) { 1280 NL_SET_ERR_MSG(extack, 1281 "Specified parent ID is reserved for ingress and clsact Qdiscs"); 1282 err = -EINVAL; 1283 goto err_out3; 1284 } 1285 handle = TC_H_MAKE(TC_H_INGRESS, 0); 1286 } else { 1287 if (handle == 0) { 1288 handle = qdisc_alloc_handle(dev); 1289 if (handle == 0) { 1290 NL_SET_ERR_MSG(extack, "Maximum number of qdisc handles was exceeded"); 1291 err = -ENOSPC; 1292 goto err_out3; 1293 } 1294 } 1295 if (!netif_is_multiqueue(dev)) 1296 sch->flags |= TCQ_F_ONETXQUEUE; 1297 } 1298 1299 sch->handle = handle; 1300 1301 /* This exist to keep backward compatible with a userspace 1302 * loophole, what allowed userspace to get IFF_NO_QUEUE 1303 * facility on older kernels by setting tx_queue_len=0 (prior 1304 * to qdisc init), and then forgot to reinit tx_queue_len 1305 * before again attaching a qdisc. 1306 */ 1307 if ((dev->priv_flags & IFF_NO_QUEUE) && (dev->tx_queue_len == 0)) { 1308 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 1309 netdev_info(dev, "Caught tx_queue_len zero misconfig\n"); 1310 } 1311 1312 err = qdisc_block_indexes_set(sch, tca, extack); 1313 if (err) 1314 goto err_out3; 1315 1316 if (tca[TCA_STAB]) { 1317 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1318 if (IS_ERR(stab)) { 1319 err = PTR_ERR(stab); 1320 goto err_out3; 1321 } 1322 rcu_assign_pointer(sch->stab, stab); 1323 } 1324 1325 if (ops->init) { 1326 err = ops->init(sch, tca[TCA_OPTIONS], extack); 1327 if (err != 0) 1328 goto err_out4; 1329 } 1330 1331 if (tca[TCA_RATE]) { 1332 err = -EOPNOTSUPP; 1333 if (sch->flags & TCQ_F_MQROOT) { 1334 NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc"); 1335 goto err_out4; 1336 } 1337 1338 err = gen_new_estimator(&sch->bstats, 1339 sch->cpu_bstats, 1340 &sch->rate_est, 1341 NULL, 1342 true, 1343 tca[TCA_RATE]); 1344 if (err) { 1345 NL_SET_ERR_MSG(extack, "Failed to generate new estimator"); 1346 goto err_out4; 1347 } 1348 } 1349 1350 qdisc_hash_add(sch, false); 1351 trace_qdisc_create(ops, dev, parent); 1352 1353 return sch; 1354 1355 err_out4: 1356 /* Even if ops->init() failed, we call ops->destroy() 1357 * like qdisc_create_dflt(). 1358 */ 1359 if (ops->destroy) 1360 ops->destroy(sch); 1361 qdisc_put_stab(rtnl_dereference(sch->stab)); 1362 err_out3: 1363 lockdep_unregister_key(&sch->root_lock_key); 1364 netdev_put(dev, &sch->dev_tracker); 1365 qdisc_free(sch); 1366 err_out2: 1367 module_put(ops->owner); 1368 err_out: 1369 *errp = err; 1370 return NULL; 1371 } 1372 1373 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca, 1374 struct netlink_ext_ack *extack) 1375 { 1376 struct qdisc_size_table *ostab, *stab = NULL; 1377 int err = 0; 1378 1379 if (tca[TCA_OPTIONS]) { 1380 if (!sch->ops->change) { 1381 NL_SET_ERR_MSG(extack, "Change operation not supported by specified qdisc"); 1382 return -EINVAL; 1383 } 1384 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 1385 NL_SET_ERR_MSG(extack, "Change of blocks is not supported"); 1386 return -EOPNOTSUPP; 1387 } 1388 err = sch->ops->change(sch, tca[TCA_OPTIONS], extack); 1389 if (err) 1390 return err; 1391 } 1392 1393 if (tca[TCA_STAB]) { 1394 stab = qdisc_get_stab(tca[TCA_STAB], extack); 1395 if (IS_ERR(stab)) 1396 return PTR_ERR(stab); 1397 } 1398 1399 ostab = rtnl_dereference(sch->stab); 1400 rcu_assign_pointer(sch->stab, stab); 1401 qdisc_put_stab(ostab); 1402 1403 if (tca[TCA_RATE]) { 1404 /* NB: ignores errors from replace_estimator 1405 because change can't be undone. */ 1406 if (sch->flags & TCQ_F_MQROOT) 1407 goto out; 1408 gen_replace_estimator(&sch->bstats, 1409 sch->cpu_bstats, 1410 &sch->rate_est, 1411 NULL, 1412 true, 1413 tca[TCA_RATE]); 1414 } 1415 out: 1416 return 0; 1417 } 1418 1419 struct check_loop_arg { 1420 struct qdisc_walker w; 1421 struct Qdisc *p; 1422 int depth; 1423 }; 1424 1425 static int check_loop_fn(struct Qdisc *q, unsigned long cl, 1426 struct qdisc_walker *w); 1427 1428 static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) 1429 { 1430 struct check_loop_arg arg; 1431 1432 if (q->ops->cl_ops == NULL) 1433 return 0; 1434 1435 arg.w.stop = arg.w.skip = arg.w.count = 0; 1436 arg.w.fn = check_loop_fn; 1437 arg.depth = depth; 1438 arg.p = p; 1439 q->ops->cl_ops->walk(q, &arg.w); 1440 return arg.w.stop ? -ELOOP : 0; 1441 } 1442 1443 static int 1444 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) 1445 { 1446 struct Qdisc *leaf; 1447 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 1448 struct check_loop_arg *arg = (struct check_loop_arg *)w; 1449 1450 leaf = cops->leaf(q, cl); 1451 if (leaf) { 1452 if (leaf == arg->p || arg->depth > 7) 1453 return -ELOOP; 1454 return check_loop(leaf, arg->p, arg->depth + 1); 1455 } 1456 return 0; 1457 } 1458 1459 const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = { 1460 [TCA_KIND] = { .type = NLA_STRING }, 1461 [TCA_RATE] = { .type = NLA_BINARY, 1462 .len = sizeof(struct tc_estimator) }, 1463 [TCA_STAB] = { .type = NLA_NESTED }, 1464 [TCA_DUMP_INVISIBLE] = { .type = NLA_FLAG }, 1465 [TCA_CHAIN] = { .type = NLA_U32 }, 1466 [TCA_INGRESS_BLOCK] = { .type = NLA_U32 }, 1467 [TCA_EGRESS_BLOCK] = { .type = NLA_U32 }, 1468 }; 1469 1470 /* 1471 * Delete/get qdisc. 1472 */ 1473 1474 static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1475 struct netlink_ext_ack *extack) 1476 { 1477 struct net *net = sock_net(skb->sk); 1478 struct tcmsg *tcm = nlmsg_data(n); 1479 struct nlattr *tca[TCA_MAX + 1]; 1480 struct net_device *dev; 1481 u32 clid; 1482 struct Qdisc *q = NULL; 1483 struct Qdisc *p = NULL; 1484 int err; 1485 1486 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1487 rtm_tca_policy, extack); 1488 if (err < 0) 1489 return err; 1490 1491 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1492 if (!dev) 1493 return -ENODEV; 1494 1495 clid = tcm->tcm_parent; 1496 if (clid) { 1497 if (clid != TC_H_ROOT) { 1498 if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { 1499 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1500 if (!p) { 1501 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified classid"); 1502 return -ENOENT; 1503 } 1504 q = qdisc_leaf(p, clid); 1505 } else if (dev_ingress_queue(dev)) { 1506 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1507 } 1508 } else { 1509 q = rtnl_dereference(dev->qdisc); 1510 } 1511 if (!q) { 1512 NL_SET_ERR_MSG(extack, "Cannot find specified qdisc on specified device"); 1513 return -ENOENT; 1514 } 1515 1516 if (tcm->tcm_handle && q->handle != tcm->tcm_handle) { 1517 NL_SET_ERR_MSG(extack, "Invalid handle"); 1518 return -EINVAL; 1519 } 1520 } else { 1521 q = qdisc_lookup(dev, tcm->tcm_handle); 1522 if (!q) { 1523 NL_SET_ERR_MSG(extack, "Failed to find qdisc with specified handle"); 1524 return -ENOENT; 1525 } 1526 } 1527 1528 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1529 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1530 return -EINVAL; 1531 } 1532 1533 if (n->nlmsg_type == RTM_DELQDISC) { 1534 if (!clid) { 1535 NL_SET_ERR_MSG(extack, "Classid cannot be zero"); 1536 return -EINVAL; 1537 } 1538 if (q->handle == 0) { 1539 NL_SET_ERR_MSG(extack, "Cannot delete qdisc with handle of zero"); 1540 return -ENOENT; 1541 } 1542 err = qdisc_graft(dev, p, skb, n, clid, NULL, q, extack); 1543 if (err != 0) 1544 return err; 1545 } else { 1546 qdisc_notify(net, skb, n, clid, NULL, q, NULL); 1547 } 1548 return 0; 1549 } 1550 1551 static bool req_create_or_replace(struct nlmsghdr *n) 1552 { 1553 return (n->nlmsg_flags & NLM_F_CREATE && 1554 n->nlmsg_flags & NLM_F_REPLACE); 1555 } 1556 1557 static bool req_create_exclusive(struct nlmsghdr *n) 1558 { 1559 return (n->nlmsg_flags & NLM_F_CREATE && 1560 n->nlmsg_flags & NLM_F_EXCL); 1561 } 1562 1563 static bool req_change(struct nlmsghdr *n) 1564 { 1565 return (!(n->nlmsg_flags & NLM_F_CREATE) && 1566 !(n->nlmsg_flags & NLM_F_REPLACE) && 1567 !(n->nlmsg_flags & NLM_F_EXCL)); 1568 } 1569 1570 /* 1571 * Create/change qdisc. 1572 */ 1573 static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, 1574 struct netlink_ext_ack *extack) 1575 { 1576 struct net *net = sock_net(skb->sk); 1577 struct tcmsg *tcm; 1578 struct nlattr *tca[TCA_MAX + 1]; 1579 struct net_device *dev; 1580 u32 clid; 1581 struct Qdisc *q, *p; 1582 int err; 1583 1584 replay: 1585 /* Reinit, just in case something touches this. */ 1586 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 1587 rtm_tca_policy, extack); 1588 if (err < 0) 1589 return err; 1590 1591 tcm = nlmsg_data(n); 1592 clid = tcm->tcm_parent; 1593 q = p = NULL; 1594 1595 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 1596 if (!dev) 1597 return -ENODEV; 1598 1599 1600 if (clid) { 1601 if (clid != TC_H_ROOT) { 1602 if (clid != TC_H_INGRESS) { 1603 p = qdisc_lookup(dev, TC_H_MAJ(clid)); 1604 if (!p) { 1605 NL_SET_ERR_MSG(extack, "Failed to find specified qdisc"); 1606 return -ENOENT; 1607 } 1608 q = qdisc_leaf(p, clid); 1609 } else if (dev_ingress_queue_create(dev)) { 1610 q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); 1611 } 1612 } else { 1613 q = rtnl_dereference(dev->qdisc); 1614 } 1615 1616 /* It may be default qdisc, ignore it */ 1617 if (q && q->handle == 0) 1618 q = NULL; 1619 1620 if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { 1621 if (tcm->tcm_handle) { 1622 if (q && !(n->nlmsg_flags & NLM_F_REPLACE)) { 1623 NL_SET_ERR_MSG(extack, "NLM_F_REPLACE needed to override"); 1624 return -EEXIST; 1625 } 1626 if (TC_H_MIN(tcm->tcm_handle)) { 1627 NL_SET_ERR_MSG(extack, "Invalid minor handle"); 1628 return -EINVAL; 1629 } 1630 q = qdisc_lookup(dev, tcm->tcm_handle); 1631 if (!q) 1632 goto create_n_graft; 1633 if (n->nlmsg_flags & NLM_F_EXCL) { 1634 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot override"); 1635 return -EEXIST; 1636 } 1637 if (tca[TCA_KIND] && 1638 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1639 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1640 return -EINVAL; 1641 } 1642 if (q->flags & TCQ_F_INGRESS) { 1643 NL_SET_ERR_MSG(extack, 1644 "Cannot regraft ingress or clsact Qdiscs"); 1645 return -EINVAL; 1646 } 1647 if (q == p || 1648 (p && check_loop(q, p, 0))) { 1649 NL_SET_ERR_MSG(extack, "Qdisc parent/child loop detected"); 1650 return -ELOOP; 1651 } 1652 if (clid == TC_H_INGRESS) { 1653 NL_SET_ERR_MSG(extack, "Ingress cannot graft directly"); 1654 return -EINVAL; 1655 } 1656 qdisc_refcount_inc(q); 1657 goto graft; 1658 } else { 1659 if (!q) 1660 goto create_n_graft; 1661 1662 /* This magic test requires explanation. 1663 * 1664 * We know, that some child q is already 1665 * attached to this parent and have choice: 1666 * 1) change it or 2) create/graft new one. 1667 * If the requested qdisc kind is different 1668 * than the existing one, then we choose graft. 1669 * If they are the same then this is "change" 1670 * operation - just let it fallthrough.. 1671 * 1672 * 1. We are allowed to create/graft only 1673 * if the request is explicitly stating 1674 * "please create if it doesn't exist". 1675 * 1676 * 2. If the request is to exclusive create 1677 * then the qdisc tcm_handle is not expected 1678 * to exist, so that we choose create/graft too. 1679 * 1680 * 3. The last case is when no flags are set. 1681 * This will happen when for example tc 1682 * utility issues a "change" command. 1683 * Alas, it is sort of hole in API, we 1684 * cannot decide what to do unambiguously. 1685 * For now we select create/graft. 1686 */ 1687 if (tca[TCA_KIND] && 1688 nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1689 if (req_create_or_replace(n) || 1690 req_create_exclusive(n)) 1691 goto create_n_graft; 1692 else if (req_change(n)) 1693 goto create_n_graft2; 1694 } 1695 } 1696 } 1697 } else { 1698 if (!tcm->tcm_handle) { 1699 NL_SET_ERR_MSG(extack, "Handle cannot be zero"); 1700 return -EINVAL; 1701 } 1702 q = qdisc_lookup(dev, tcm->tcm_handle); 1703 } 1704 1705 /* Change qdisc parameters */ 1706 if (!q) { 1707 NL_SET_ERR_MSG(extack, "Specified qdisc not found"); 1708 return -ENOENT; 1709 } 1710 if (n->nlmsg_flags & NLM_F_EXCL) { 1711 NL_SET_ERR_MSG(extack, "Exclusivity flag on, cannot modify"); 1712 return -EEXIST; 1713 } 1714 if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], q->ops->id)) { 1715 NL_SET_ERR_MSG(extack, "Invalid qdisc name"); 1716 return -EINVAL; 1717 } 1718 err = qdisc_change(q, tca, extack); 1719 if (err == 0) 1720 qdisc_notify(net, skb, n, clid, NULL, q, extack); 1721 return err; 1722 1723 create_n_graft: 1724 if (!(n->nlmsg_flags & NLM_F_CREATE)) { 1725 NL_SET_ERR_MSG(extack, "Qdisc not found. To create specify NLM_F_CREATE flag"); 1726 return -ENOENT; 1727 } 1728 create_n_graft2: 1729 if (clid == TC_H_INGRESS) { 1730 if (dev_ingress_queue(dev)) { 1731 q = qdisc_create(dev, dev_ingress_queue(dev), 1732 tcm->tcm_parent, tcm->tcm_parent, 1733 tca, &err, extack); 1734 } else { 1735 NL_SET_ERR_MSG(extack, "Cannot find ingress queue for specified device"); 1736 err = -ENOENT; 1737 } 1738 } else { 1739 struct netdev_queue *dev_queue; 1740 1741 if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue) 1742 dev_queue = p->ops->cl_ops->select_queue(p, tcm); 1743 else if (p) 1744 dev_queue = p->dev_queue; 1745 else 1746 dev_queue = netdev_get_tx_queue(dev, 0); 1747 1748 q = qdisc_create(dev, dev_queue, 1749 tcm->tcm_parent, tcm->tcm_handle, 1750 tca, &err, extack); 1751 } 1752 if (q == NULL) { 1753 if (err == -EAGAIN) 1754 goto replay; 1755 return err; 1756 } 1757 1758 graft: 1759 err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack); 1760 if (err) { 1761 if (q) 1762 qdisc_put(q); 1763 return err; 1764 } 1765 1766 return 0; 1767 } 1768 1769 static int tc_dump_qdisc_root(struct Qdisc *root, struct sk_buff *skb, 1770 struct netlink_callback *cb, 1771 int *q_idx_p, int s_q_idx, bool recur, 1772 bool dump_invisible) 1773 { 1774 int ret = 0, q_idx = *q_idx_p; 1775 struct Qdisc *q; 1776 int b; 1777 1778 if (!root) 1779 return 0; 1780 1781 q = root; 1782 if (q_idx < s_q_idx) { 1783 q_idx++; 1784 } else { 1785 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1786 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1787 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1788 RTM_NEWQDISC, NULL) <= 0) 1789 goto done; 1790 q_idx++; 1791 } 1792 1793 /* If dumping singletons, there is no qdisc_dev(root) and the singleton 1794 * itself has already been dumped. 1795 * 1796 * If we've already dumped the top-level (ingress) qdisc above and the global 1797 * qdisc hashtable, we don't want to hit it again 1798 */ 1799 if (!qdisc_dev(root) || !recur) 1800 goto out; 1801 1802 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 1803 if (q_idx < s_q_idx) { 1804 q_idx++; 1805 continue; 1806 } 1807 if (!tc_qdisc_dump_ignore(q, dump_invisible) && 1808 tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).portid, 1809 cb->nlh->nlmsg_seq, NLM_F_MULTI, 1810 RTM_NEWQDISC, NULL) <= 0) 1811 goto done; 1812 q_idx++; 1813 } 1814 1815 out: 1816 *q_idx_p = q_idx; 1817 return ret; 1818 done: 1819 ret = -1; 1820 goto out; 1821 } 1822 1823 static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) 1824 { 1825 struct net *net = sock_net(skb->sk); 1826 int idx, q_idx; 1827 int s_idx, s_q_idx; 1828 struct net_device *dev; 1829 const struct nlmsghdr *nlh = cb->nlh; 1830 struct nlattr *tca[TCA_MAX + 1]; 1831 int err; 1832 1833 s_idx = cb->args[0]; 1834 s_q_idx = q_idx = cb->args[1]; 1835 1836 idx = 0; 1837 ASSERT_RTNL(); 1838 1839 err = nlmsg_parse_deprecated(nlh, sizeof(struct tcmsg), tca, TCA_MAX, 1840 rtm_tca_policy, cb->extack); 1841 if (err < 0) 1842 return err; 1843 1844 for_each_netdev(net, dev) { 1845 struct netdev_queue *dev_queue; 1846 1847 if (idx < s_idx) 1848 goto cont; 1849 if (idx > s_idx) 1850 s_q_idx = 0; 1851 q_idx = 0; 1852 1853 if (tc_dump_qdisc_root(rtnl_dereference(dev->qdisc), 1854 skb, cb, &q_idx, s_q_idx, 1855 true, tca[TCA_DUMP_INVISIBLE]) < 0) 1856 goto done; 1857 1858 dev_queue = dev_ingress_queue(dev); 1859 if (dev_queue && 1860 tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping), 1861 skb, cb, &q_idx, s_q_idx, false, 1862 tca[TCA_DUMP_INVISIBLE]) < 0) 1863 goto done; 1864 1865 cont: 1866 idx++; 1867 } 1868 1869 done: 1870 cb->args[0] = idx; 1871 cb->args[1] = q_idx; 1872 1873 return skb->len; 1874 } 1875 1876 1877 1878 /************************************************ 1879 * Traffic classes manipulation. * 1880 ************************************************/ 1881 1882 static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, 1883 unsigned long cl, u32 portid, u32 seq, u16 flags, 1884 int event, struct netlink_ext_ack *extack) 1885 { 1886 struct tcmsg *tcm; 1887 struct nlmsghdr *nlh; 1888 unsigned char *b = skb_tail_pointer(skb); 1889 struct gnet_dump d; 1890 const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; 1891 1892 cond_resched(); 1893 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); 1894 if (!nlh) 1895 goto out_nlmsg_trim; 1896 tcm = nlmsg_data(nlh); 1897 tcm->tcm_family = AF_UNSPEC; 1898 tcm->tcm__pad1 = 0; 1899 tcm->tcm__pad2 = 0; 1900 tcm->tcm_ifindex = qdisc_dev(q)->ifindex; 1901 tcm->tcm_parent = q->handle; 1902 tcm->tcm_handle = q->handle; 1903 tcm->tcm_info = 0; 1904 if (nla_put_string(skb, TCA_KIND, q->ops->id)) 1905 goto nla_put_failure; 1906 if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) 1907 goto nla_put_failure; 1908 1909 if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS, 1910 NULL, &d, TCA_PAD) < 0) 1911 goto nla_put_failure; 1912 1913 if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) 1914 goto nla_put_failure; 1915 1916 if (gnet_stats_finish_copy(&d) < 0) 1917 goto nla_put_failure; 1918 1919 if (extack && extack->_msg && 1920 nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg)) 1921 goto out_nlmsg_trim; 1922 1923 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 1924 1925 return skb->len; 1926 1927 out_nlmsg_trim: 1928 nla_put_failure: 1929 nlmsg_trim(skb, b); 1930 return -1; 1931 } 1932 1933 static int tclass_notify(struct net *net, struct sk_buff *oskb, 1934 struct nlmsghdr *n, struct Qdisc *q, 1935 unsigned long cl, int event, struct netlink_ext_ack *extack) 1936 { 1937 struct sk_buff *skb; 1938 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1939 1940 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1941 if (!skb) 1942 return -ENOBUFS; 1943 1944 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, event, extack) < 0) { 1945 kfree_skb(skb); 1946 return -EINVAL; 1947 } 1948 1949 return rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1950 n->nlmsg_flags & NLM_F_ECHO); 1951 } 1952 1953 static int tclass_del_notify(struct net *net, 1954 const struct Qdisc_class_ops *cops, 1955 struct sk_buff *oskb, struct nlmsghdr *n, 1956 struct Qdisc *q, unsigned long cl, 1957 struct netlink_ext_ack *extack) 1958 { 1959 u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; 1960 struct sk_buff *skb; 1961 int err = 0; 1962 1963 if (!cops->delete) 1964 return -EOPNOTSUPP; 1965 1966 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1967 if (!skb) 1968 return -ENOBUFS; 1969 1970 if (tc_fill_tclass(skb, q, cl, portid, n->nlmsg_seq, 0, 1971 RTM_DELTCLASS, extack) < 0) { 1972 kfree_skb(skb); 1973 return -EINVAL; 1974 } 1975 1976 err = cops->delete(q, cl, extack); 1977 if (err) { 1978 kfree_skb(skb); 1979 return err; 1980 } 1981 1982 err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, 1983 n->nlmsg_flags & NLM_F_ECHO); 1984 return err; 1985 } 1986 1987 #ifdef CONFIG_NET_CLS 1988 1989 struct tcf_bind_args { 1990 struct tcf_walker w; 1991 unsigned long base; 1992 unsigned long cl; 1993 u32 classid; 1994 }; 1995 1996 static int tcf_node_bind(struct tcf_proto *tp, void *n, struct tcf_walker *arg) 1997 { 1998 struct tcf_bind_args *a = (void *)arg; 1999 2000 if (n && tp->ops->bind_class) { 2001 struct Qdisc *q = tcf_block_q(tp->chain->block); 2002 2003 sch_tree_lock(q); 2004 tp->ops->bind_class(n, a->classid, a->cl, q, a->base); 2005 sch_tree_unlock(q); 2006 } 2007 return 0; 2008 } 2009 2010 struct tc_bind_class_args { 2011 struct qdisc_walker w; 2012 unsigned long new_cl; 2013 u32 portid; 2014 u32 clid; 2015 }; 2016 2017 static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl, 2018 struct qdisc_walker *w) 2019 { 2020 struct tc_bind_class_args *a = (struct tc_bind_class_args *)w; 2021 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2022 struct tcf_block *block; 2023 struct tcf_chain *chain; 2024 2025 block = cops->tcf_block(q, cl, NULL); 2026 if (!block) 2027 return 0; 2028 for (chain = tcf_get_next_chain(block, NULL); 2029 chain; 2030 chain = tcf_get_next_chain(block, chain)) { 2031 struct tcf_proto *tp; 2032 2033 for (tp = tcf_get_next_proto(chain, NULL); 2034 tp; tp = tcf_get_next_proto(chain, tp)) { 2035 struct tcf_bind_args arg = {}; 2036 2037 arg.w.fn = tcf_node_bind; 2038 arg.classid = a->clid; 2039 arg.base = cl; 2040 arg.cl = a->new_cl; 2041 tp->ops->walk(tp, &arg.w, true); 2042 } 2043 } 2044 2045 return 0; 2046 } 2047 2048 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2049 unsigned long new_cl) 2050 { 2051 const struct Qdisc_class_ops *cops = q->ops->cl_ops; 2052 struct tc_bind_class_args args = {}; 2053 2054 if (!cops->tcf_block) 2055 return; 2056 args.portid = portid; 2057 args.clid = clid; 2058 args.new_cl = new_cl; 2059 args.w.fn = tc_bind_class_walker; 2060 q->ops->cl_ops->walk(q, &args.w); 2061 } 2062 2063 #else 2064 2065 static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid, 2066 unsigned long new_cl) 2067 { 2068 } 2069 2070 #endif 2071 2072 static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, 2073 struct netlink_ext_ack *extack) 2074 { 2075 struct net *net = sock_net(skb->sk); 2076 struct tcmsg *tcm = nlmsg_data(n); 2077 struct nlattr *tca[TCA_MAX + 1]; 2078 struct net_device *dev; 2079 struct Qdisc *q = NULL; 2080 const struct Qdisc_class_ops *cops; 2081 unsigned long cl = 0; 2082 unsigned long new_cl; 2083 u32 portid; 2084 u32 clid; 2085 u32 qid; 2086 int err; 2087 2088 err = nlmsg_parse_deprecated(n, sizeof(*tcm), tca, TCA_MAX, 2089 rtm_tca_policy, extack); 2090 if (err < 0) 2091 return err; 2092 2093 dev = __dev_get_by_index(net, tcm->tcm_ifindex); 2094 if (!dev) 2095 return -ENODEV; 2096 2097 /* 2098 parent == TC_H_UNSPEC - unspecified parent. 2099 parent == TC_H_ROOT - class is root, which has no parent. 2100 parent == X:0 - parent is root class. 2101 parent == X:Y - parent is a node in hierarchy. 2102 parent == 0:Y - parent is X:Y, where X:0 is qdisc. 2103 2104 handle == 0:0 - generate handle from kernel pool. 2105 handle == 0:Y - class is X:Y, where X:0 is qdisc. 2106 handle == X:Y - clear. 2107 handle == X:0 - root class. 2108 */ 2109 2110 /* Step 1. Determine qdisc handle X:0 */ 2111 2112 portid = tcm->tcm_parent; 2113 clid = tcm->tcm_handle; 2114 qid = TC_H_MAJ(clid); 2115 2116 if (portid != TC_H_ROOT) { 2117 u32 qid1 = TC_H_MAJ(portid); 2118 2119 if (qid && qid1) { 2120 /* If both majors are known, they must be identical. */ 2121 if (qid != qid1) 2122 return -EINVAL; 2123 } else if (qid1) { 2124 qid = qid1; 2125 } else if (qid == 0) 2126 qid = rtnl_dereference(dev->qdisc)->handle; 2127 2128 /* Now qid is genuine qdisc handle consistent 2129 * both with parent and child. 2130 * 2131 * TC_H_MAJ(portid) still may be unspecified, complete it now. 2132 */ 2133 if (portid) 2134 portid = TC_H_MAKE(qid, portid); 2135 } else { 2136 if (qid == 0) 2137 qid = rtnl_dereference(dev->qdisc)->handle; 2138 } 2139 2140 /* OK. Locate qdisc */ 2141 q = qdisc_lookup(dev, qid); 2142 if (!q) 2143 return -ENOENT; 2144 2145 /* An check that it supports classes */ 2146 cops = q->ops->cl_ops; 2147 if (cops == NULL) 2148 return -EINVAL; 2149 2150 /* Now try to get class */ 2151 if (clid == 0) { 2152 if (portid == TC_H_ROOT) 2153 clid = qid; 2154 } else 2155 clid = TC_H_MAKE(qid, clid); 2156 2157 if (clid) 2158 cl = cops->find(q, clid); 2159 2160 if (cl == 0) { 2161 err = -ENOENT; 2162 if (n->nlmsg_type != RTM_NEWTCLASS || 2163 !(n->nlmsg_flags & NLM_F_CREATE)) 2164 goto out; 2165 } else { 2166 switch (n->nlmsg_type) { 2167 case RTM_NEWTCLASS: 2168 err = -EEXIST; 2169 if (n->nlmsg_flags & NLM_F_EXCL) 2170 goto out; 2171 break; 2172 case RTM_DELTCLASS: 2173 err = tclass_del_notify(net, cops, skb, n, q, cl, extack); 2174 /* Unbind the class with flilters with 0 */ 2175 tc_bind_tclass(q, portid, clid, 0); 2176 goto out; 2177 case RTM_GETTCLASS: 2178 err = tclass_notify(net, skb, n, q, cl, RTM_NEWTCLASS, extack); 2179 goto out; 2180 default: 2181 err = -EINVAL; 2182 goto out; 2183 } 2184 } 2185 2186 if (tca[TCA_INGRESS_BLOCK] || tca[TCA_EGRESS_BLOCK]) { 2187 NL_SET_ERR_MSG(extack, "Shared blocks are not supported for classes"); 2188 return -EOPNOTSUPP; 2189 } 2190 2191 new_cl = cl; 2192 err = -EOPNOTSUPP; 2193 if (cops->change) 2194 err = cops->change(q, clid, portid, tca, &new_cl, extack); 2195 if (err == 0) { 2196 tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS, extack); 2197 /* We just create a new class, need to do reverse binding. */ 2198 if (cl != new_cl) 2199 tc_bind_tclass(q, portid, clid, new_cl); 2200 } 2201 out: 2202 return err; 2203 } 2204 2205 struct qdisc_dump_args { 2206 struct qdisc_walker w; 2207 struct sk_buff *skb; 2208 struct netlink_callback *cb; 2209 }; 2210 2211 static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, 2212 struct qdisc_walker *arg) 2213 { 2214 struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; 2215 2216 return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).portid, 2217 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, 2218 RTM_NEWTCLASS, NULL); 2219 } 2220 2221 static int tc_dump_tclass_qdisc(struct Qdisc *q, struct sk_buff *skb, 2222 struct tcmsg *tcm, struct netlink_callback *cb, 2223 int *t_p, int s_t) 2224 { 2225 struct qdisc_dump_args arg; 2226 2227 if (tc_qdisc_dump_ignore(q, false) || 2228 *t_p < s_t || !q->ops->cl_ops || 2229 (tcm->tcm_parent && 2230 TC_H_MAJ(tcm->tcm_parent) != q->handle)) { 2231 (*t_p)++; 2232 return 0; 2233 } 2234 if (*t_p > s_t) 2235 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 2236 arg.w.fn = qdisc_class_dump; 2237 arg.skb = skb; 2238 arg.cb = cb; 2239 arg.w.stop = 0; 2240 arg.w.skip = cb->args[1]; 2241 arg.w.count = 0; 2242 q->ops->cl_ops->walk(q, &arg.w); 2243 cb->args[1] = arg.w.count; 2244 if (arg.w.stop) 2245 return -1; 2246 (*t_p)++; 2247 return 0; 2248 } 2249 2250 static int tc_dump_tclass_root(struct Qdisc *root, struct sk_buff *skb, 2251 struct tcmsg *tcm, struct netlink_callback *cb, 2252 int *t_p, int s_t, bool recur) 2253 { 2254 struct Qdisc *q; 2255 int b; 2256 2257 if (!root) 2258 return 0; 2259 2260 if (tc_dump_tclass_qdisc(root, skb, tcm, cb, t_p, s_t) < 0) 2261 return -1; 2262 2263 if (!qdisc_dev(root) || !recur) 2264 return 0; 2265 2266 if (tcm->tcm_parent) { 2267 q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent)); 2268 if (q && q != root && 2269 tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2270 return -1; 2271 return 0; 2272 } 2273 hash_for_each(qdisc_dev(root)->qdisc_hash, b, q, hash) { 2274 if (tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) 2275 return -1; 2276 } 2277 2278 return 0; 2279 } 2280 2281 static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) 2282 { 2283 struct tcmsg *tcm = nlmsg_data(cb->nlh); 2284 struct net *net = sock_net(skb->sk); 2285 struct netdev_queue *dev_queue; 2286 struct net_device *dev; 2287 int t, s_t; 2288 2289 if (nlmsg_len(cb->nlh) < sizeof(*tcm)) 2290 return 0; 2291 dev = dev_get_by_index(net, tcm->tcm_ifindex); 2292 if (!dev) 2293 return 0; 2294 2295 s_t = cb->args[0]; 2296 t = 0; 2297 2298 if (tc_dump_tclass_root(rtnl_dereference(dev->qdisc), 2299 skb, tcm, cb, &t, s_t, true) < 0) 2300 goto done; 2301 2302 dev_queue = dev_ingress_queue(dev); 2303 if (dev_queue && 2304 tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping), 2305 skb, tcm, cb, &t, s_t, false) < 0) 2306 goto done; 2307 2308 done: 2309 cb->args[0] = t; 2310 2311 dev_put(dev); 2312 return skb->len; 2313 } 2314 2315 #ifdef CONFIG_PROC_FS 2316 static int psched_show(struct seq_file *seq, void *v) 2317 { 2318 seq_printf(seq, "%08x %08x %08x %08x\n", 2319 (u32)NSEC_PER_USEC, (u32)PSCHED_TICKS2NS(1), 2320 1000000, 2321 (u32)NSEC_PER_SEC / hrtimer_resolution); 2322 2323 return 0; 2324 } 2325 2326 static int __net_init psched_net_init(struct net *net) 2327 { 2328 struct proc_dir_entry *e; 2329 2330 e = proc_create_single("psched", 0, net->proc_net, psched_show); 2331 if (e == NULL) 2332 return -ENOMEM; 2333 2334 return 0; 2335 } 2336 2337 static void __net_exit psched_net_exit(struct net *net) 2338 { 2339 remove_proc_entry("psched", net->proc_net); 2340 } 2341 #else 2342 static int __net_init psched_net_init(struct net *net) 2343 { 2344 return 0; 2345 } 2346 2347 static void __net_exit psched_net_exit(struct net *net) 2348 { 2349 } 2350 #endif 2351 2352 static struct pernet_operations psched_net_ops = { 2353 .init = psched_net_init, 2354 .exit = psched_net_exit, 2355 }; 2356 2357 #if IS_ENABLED(CONFIG_RETPOLINE) 2358 DEFINE_STATIC_KEY_FALSE(tc_skip_wrapper); 2359 #endif 2360 2361 static int __init pktsched_init(void) 2362 { 2363 int err; 2364 2365 err = register_pernet_subsys(&psched_net_ops); 2366 if (err) { 2367 pr_err("pktsched_init: " 2368 "cannot initialize per netns operations\n"); 2369 return err; 2370 } 2371 2372 register_qdisc(&pfifo_fast_ops); 2373 register_qdisc(&pfifo_qdisc_ops); 2374 register_qdisc(&bfifo_qdisc_ops); 2375 register_qdisc(&pfifo_head_drop_qdisc_ops); 2376 register_qdisc(&mq_qdisc_ops); 2377 register_qdisc(&noqueue_qdisc_ops); 2378 2379 rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL, 0); 2380 rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL, 0); 2381 rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc, 2382 0); 2383 rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL, 0); 2384 rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL, 0); 2385 rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass, 2386 0); 2387 2388 tc_wrapper_init(); 2389 2390 return 0; 2391 } 2392 2393 subsys_initcall(pktsched_init); 2394